This invention relates to the production of electrically conductive organic polymers. More particularly, it relates to an improved method for the electropolymerization and recovery of processable conductive polymers.
Considerable effort has been expended by researchers toward the production of polymers which exhibit electrical conductivity. For example, in ORGANIC COATINGS AND PLASTICS CHEMISTRY, Vol. 43, pp. 774-6, Preprints of Papers Presented by the Division of Organic Coatings and Plastics Chemistry at the American Chemical Society 180th National Meeting, San Francisco, Calif., Aug, 24-29, 1980, there is reported by A. F. Diaz et al., in the paper "Electrosynthesis and Study of Conducting Polymeric Films", the electropolymerization of pyrrole, using a variety of electrolyte salts as counteranions. A summary of various approaches to the creation of electrically conducting polymers is reported, for example, by J. Frommer, in "Polymer Research Frontier: How Insulators Become Conductors", Industrial Chemical News, Vol. 4, No. 10, October 1983.
Polymeric materials which have been proposed as conductive polymers, for the most part, are characterized by one or more undesirable properties, including instability under ambient conditions, poor physical integrity (notably brittleness) and poor processability (insolubility or intractability) severely limiting the production or fabrication of conductive polymeric articles by conventional production or processing techniques.
While various applications for conductive polymers have been proposed, for example, in the manufacture of solar cells and batteries and for EMI shielding, the physical properties and/or processability of a conductive polymeric material will dictate in part the suitability of such materials to particular applications. In my copending application "Processable Conductive Polymers", U.S. Ser. No. 595,667, filed Apr. 2, 1984, there is disclosed and claimed a processable electrically conductive organic material and a method for the production of such polymer. As described therein, the conductive organic polymer is prepared by the electropolymerization of an electropolymerizable monomer (such as pyrrole) in the presence of a dispersed phase of polymer having anionic surface character (e.g., a polymeric latex having anionic surface character). The dispersed polyanionic polymer serves as a counterion in affiliation with cationic charges of the electropolymerized monomer and allows for the production of a processable conductive polymer material which, for example, can be processed by convenient coating methods into electrically conductive films.
While the conductive polymer material prepared by the aforedescribed method can be processed or fabricated by resort to thermal molding, extrusion or other shaping technique, or can be incorporated into a solvent or other liquid vehicle for the coating of an electrically conductive film or layer, the conductive polymer material must first be removed from the anode on which it is formed. Typically, the anode will be comprised of platinum, gold, tin oxide on glass, indium tin oxide on glass, or the like, and the electropolymerized conductive polymer material will be recovered therefrom by peeling and/or scraping. It will be appreciated that it would be advantageous from the standpoint of convenience and economy of operation if the electropolymerized conductive polymer could be recovered from an electropolymerization operation as a processable polymer material without need for the aforementioned step of removing the polymer material from the anode on which it is formed.